Second-generation Tyrosine Kinase Inhibitors Dasatinib Research Articles

Novel Insights in TKI Resistance in BCR:: ABL1-Positive B-Cell Acute Lymphoblastic Leukemia Beyond Kinase Domain Mutations

Background and Aim Despite the introduction of tyrosine kinase inhibitors (TKIs), approximately 30% of newly diagnosed pediatric and adult BCR:: ABL1-positive B-cell acute lymphoblastic leukemia (B-ALL) patients experience relapsed or refractory disease (Biondi et al, Lancet Haematology 2018; Bassan et al, Journal of Clinical Oncology 2010). ABL1 kinase domain mutations, hindering TKI binding, explain part of the relapses and are acquired during TKI therapy but are rarely detected in newly diagnosed BCR:: ABL1-positive B-ALL patients (Baer et al, Haematologica 2022). Intrinsic TKI resistance mechanisms in BCR:: ABL1-positive B-ALL present prior to TKI treatment are less well documented. Therefore, we aimed to identify potential biomarkers for TKI sensitivity at diagnosis using primary patient samples and newly generated cell lines made from patient-derived xenografts (PDX cell lines). Patients and Methods Leukemic cells from diagnosis of BCR:: ABL1-positive B-ALL patients without ABL1-kinase domain mutations were used to measure cell survival in an ex vivo co-culture assay after imatinib (1.95-125 μM), dasatinib (1.95-125 nM), or bosutinib (0.016-2 μM) exposure. TKI sensitivity was assessed using the area under the dose-response curve (AUC), with <80 arbitrary units (AU) classified as imatinib-sensitive, 80-120 AU as intermediate, and >120 AU as resistant. Multiplex ligation-dependent probe amplification, whole exome sequencing, and RNA sequencing were performed on diagnostic material if available. ABL1 phosphorylation and expression levels were measured using (phospho)flow cytometry in patient-derived xenografts from diagnostic samples and (PDX) cell lines. Results We determined ex vivo sensitivity to imatinib, dasatinib, and bosutinib in 32 pediatric and 19 adult BCR:: ABL1-positive B-ALL patient samples. We observed a substantial variability in ex vivo imatinib response in pediatric and adult patient samples (median AUC: 98 AU; range: 16 to 281 AU). The sensitivity towards imatinib strongly correlated with the sensitivity towards second-generation TKIs dasatinib and bosutinib (rho = 0.84; p < 0.001 and rho= 0.89; p <0.001). Moreover, imatinib's AUC of samples derived from newly diagnosed patients who relapsed after TKI treatment was higher compared with those derived from patients who did not suffer from a relapse (median AUC 123 vs 84 AU; p = 0.03). We observed that an increase in ex vivo imatinib resistance was correlated with a decreased amount of phosphorylated ABL1 protein (rho=-0.92; p=0.0013) and total ABL1 protein (rho=-0.82; p=0.01) in untreated, newly diagnosed samples. Ex vivo exposure to imatinib reduced the ABL1 phosphorylation levels in both sensitive and resistant samples but resistant cells exhibited lower levels of (p)ABL1 protein, indicating reduced dependence on BCR-ABL1 signaling. The ex vivo imatinib resistance in samples carrying deletions in B-cell development genes IKZF1 and/or PAX5 was higher than in samples without these deletions (median AUC: 122 versus 80 AU; p=0.01). In addition, one imatinib-resistant patient had a p.His1038Arg mutation in ZEB2, which is recurrent in B-ALL and this gene has also been described as B-cell development gene (Studd et al, Blood Cancer Journal 2021). Interestingly, another resistant patient had a mutation in SETD2,a gene previously associated with ex vivo TKI resistance in chronic myeloid leukemia cell lines (Sheng et al, Cell Proliferation 2019). Other secondary lesions included SH2B3 inactivation lesions and CRLF2 rearrangements. These lesions were present in intermediately sensitive and resistant BCR:: ABL1-positive samples and are expected to lead to increased JAK/STAT signaling, potentially serving as a resistance mechanism for TKI. Conclusion Our study revealed that the amount of total and phosphorylated ABL1 protein was correlated with ex vivo TKI sensitivity. Newly diagnosed TKI-resistant BCR:: ABL1 samples were further characterized by somatic lesions in B-cell development genes including IKZF1. These results link the known poor prognostic value of IKZF1 deletions in BCR:: ABL1-positive B-ALL patients (van der Veer et al. Blood 2014; Fedullo et al, Haematologica 2019) with intrinsic mechanisms of TKI resistance other than tyrosine kinase domain mutations.

The tyrosine kinase inhibitor Dasatinib reduces cardiac steatosis and fibrosis in obese, type 2 diabetic mice

BackgroundCardiac steatosis is an early yet overlooked feature of diabetic cardiomyopathy. There is no available therapy to treat this condition. Tyrosine kinase inhibitors (TKIs) are used as first or second-line therapy in different types of cancer. In cancer patients with diabetes mellitus, TKIs reportedly improved glycemic control, allowing insulin discontinuation. They also reduced liver steatosis in a murine model of non-alcoholic fatty liver disease. The present study aimed to determine the therapeutic effect of the second-generation TKI Dasatinib on lipid accumulation and cardiac function in obese, type 2 diabetic mice. We also assessed if the drug impacts extra-cardiac fat tissue depots.MethodsTwo studies on 21-week-old male obese leptin receptor mutant BKS.Cg-+Leprdb/+Leprdb/OlaHsd (db/db) mice compared the effect of Dasatinib (5 mg/kg) and vehicle (10% DMSO + 90% PEG-300) given via gavage once every three days for a week or once every week for four weeks. Functional and volumetric indices were studied using echocardiography. Post-mortem analyses included the assessment of fat deposits and fibrosis using histology, and senescence using immunohistochemistry and flow cytometry. The anti-adipogenic action of Dasatinib was investigated on human bone marrow (BM)-derived mesenchymal stem cells (MSCs). Unpaired parametric or non-parametric tests were used to compare two and multiple groups as appropriate.ResultsDasatinib reduced steatosis and fibrosis in the heart of diabetic mice. The drug also reduced BM adiposity but did not affect other fat depots. These structural changes were associated with improved diastolic indexes, specifically the E/A ratio and non-flow time. Moreover, Dasatinib-treated mice had lower levels of p16 in the heart compared with vehicle-treated controls, suggesting an inhibitory impact of the drug on the senescence signalling pathway. In vitro, Dasatinib inhibited human BM-MSC viability and adipogenesis commitment.ConclusionsOur findings suggest that Dasatinib opposes heart and BM adiposity and cardiac fibrosis. In the heart, this was associated with favourable functional consequences, namely improvement in an index of diastolic function. Repurposing TKI for cardiac benefit could address the unmet need of diabetic cardiac steatosis.

Treatment-free remission after discontinuation of imatinib, dasatinib, and nilotinib in patients with chronic myeloid leukemia

Patients with chronic myeloid leukemia (CML) in the chronic phase receiving tyrosine kinase inhibitor (TKI) therapy are expected to have long-term survival outcomes comparable to those of the general population. Many clinical trials have confirmed that some patients sustain molecular responses without continuing TKI therapy. Treatment-free remission (TFR) is a new goal in treating chronic CML. The safety and outcome of TFR were studied in clinical trials after discontinuing imatinib or the second-generation TKIs dasatinib or nilotinib. TFR was safe in approximately 50% of patients who achieved a deep molecular response to TKI therapy. Patients who relapsed after discontinuing TKI responded immediately to the reintroduction of TKI. The mechanism by which TFR increases the success rate still needs to be understood. The hypothesis that the modulation of immune function and targeting of leukemic stem cells could improve the TFR is under investigation. Despite the remaining questions, the TFR has become a routine consideration for clinicians in the practice of molecular remission in patients with CML.

Long-Term Molecular Testing and Clinical Response of Tyrosine Kinase Inhibitors in Patients with Chronic Myeloid Leukemia in the Chronic Phase: 5-Year Follow-up from SIMPLICITY, a Prospective, Observational Study

Introduction Tyrosine kinase inhibitors (TKIs) are commonly used as first-line therapy for the treatment of patients with chronic myeloid leukemia in the chronic phase (CML-CP). Molecular response is monitored regularly after initiating TKI therapy and less frequently after achieving BCR::ABL1 ≤ 0.1%. Although responses to TKIs have been extensively evaluated in clinical trials, utilization of molecular testing and clinical response associated with TKI therapy is not as well understood in real-world settings. SIMPLICITY (NCT01244750) is a prospective observational study assessing TKI use, molecular testing patterns, and clinical response in patients with CML-CP in routine clinical practice. Methods The SIMPLICITY study followed patients with CML-CP from routine clinical practice who received first-line treatment with the first-generation TKI imatinib (IM) or second-generation TKIs dasatinib (DAS) or nilotinib (NIL) in the USA and Europe. As this was an observational study, molecular testing was performed at the discretion of the treating team without directives from the study protocol. The cumulative proportion of US patients who underwent ≥ 1 molecular test as well as the rates of major molecular response (MMR; BCR::ABL1 ≤ 0.1%) and deep (4.5-log) molecular response (MR4.5; BCR::ABL1 < 0.0032%) were evaluated through 3 and 6 months, and yearly through 5 years, after starting TKI treatment. Patients were stratified by index TKI (IM or DAS/NIL). Descriptive statistics are presented. Results At data cutoff (January 28, 2020), a total of 810 prospective US patients were enrolled and included in this analysis, of whom 244 received IM and 566 received DAS/NIL. The median age (range) at diagnosis was 56 (18-91) years (IM, 58 [18-90] years; DAS/NIL, 55 [19-91] years). A total of 796 (98.3%) patients were followed through 3 months from the start of index TKI treatment, 792 (97.8%) through 6 months, 762 (94.1%) through 1 year, 704 (86.9%) through 2 years, 652 (80.5%) through 3 years, 590 (72.8%) through 4 years, and 538 (66.4%) through 5 years. Of those followed, the overall proportion of patients tested for molecular response ranged from 20.7% through 3 months to 92.2% through 5 years (Figure). The proportion of assessed patients who achieved MMR at least once increased over time; MMR was achieved in 15.8% of patients assessed through 3 months (IM, 11.1%; DAS/NIL, 17.1%), 35.0% through 6 months (IM, 28.7%; DAS/NIL, 36.8%), 58.2% through 1 year (IM, 51.6%; DAS/NIL, 60.5%), 77.4% through 2 years (IM, 72.9%; DAS/NIL, 79.2%), 86.6% through 3 years (IM, 84.8%; DAS/NIL, 87.3%), 92.5% through 4 years (IM, 90.6%; DAS/NIL, 93.4%), and 95.4% through 5 years (IM, 95.9%; DAS/NIL, 95.2%). The proportion of patients who achieved MR4.5 at least once also increased over time; MR4.5 was achieved in 6.1% of patients assessed through 3 months (IM, 2.8%; DAS/NIL, 7.0%), 15.9% through 6 months (IM, 9.2%; DAS/NIL, 17.9%), 32.5% through 1 year (IM, 23.4%; DAS/NIL, 35.6%), 50.2% through 2 years (IM, 41.3%; DAS/NIL, 53.6%), 63.8% through 3 years (IM, 54.9%; DAS/NIL, 67.4%), 73.8% through 4 years (IM, 67.9%; DAS/NIL, 76.3%), and 79.2% through 5 years (IM, 75.9%; DAS/NIL, 80.6%). Among all 810 enrolled patients, 473 (58.4%) and 393 (48.5%) achieved MMR and MR4.5, respectively, and remained in the study through 5 years. Mean (standard deviation) time from index TKI to best response in tested patients was 2.4 (0.5) months among patients assessed through 3 months and 24.4 (15.4) months among those assessed through 5 years. Conclusions At 5-year follow-up in US patients from the SIMPLICITY study, there was a consistent increase in the proportion of assessed patients who achieved MMR and MR4.5 over time for all patients treated with TKIs, with the caveat that patients who remained on treatment at each subsequent time point were more likely to respond. In general, a consistently higher proportion of patients treated with DAS/NIL achieved MR4.5 across the time points assessed compared with IM in this non-controlled study. Further studies evaluating molecular response to IM, DAS, NIL, and other TKIs beyond 5 years can help delineate further differences in outcomes and determine whether molecular testing frequency correlates with outcomes. Study support This study was funded by Bristol Myers Squibb. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

CML-337 Therapeutic Results of Second-Generation TKIs in a CML Multicentric Study in the West Region of Algeria

Historically, treatments for chronic myeloid leukemia (CML) are palliative, except for bone marrow allograft. Despite the results obtained using imatinib, a first-generation tyrosine kinase inhibitor (TKI), some patients (pts) have weak responses. The second-generation TKIs dasatinib and nilotinib are therapeutic alternatives in pts resistant to imatinib. This retrospective, multicenter study included 7 hematology centers in western Algeria. Pts older than 15 years treated with dasatinib or nilotinib as second-line therapy were included. The analysis of prognostic factors and the study of therapeutic responses were conducted according to ELN 2013. Event-free survival, progression-free survival, and overall survival (OS) were calculated according to the Kaplan-Meier method. Between January 2007 and December 2018, we collected 494 pts with CML, 154 of whom were treated with second-generation TKIs at a median age of 45 years (16, 83). The sex ratio was 0.87. The average splenic overflow was 8 cm. The average leukocytosis was 100 Giga/L. The average hemoglobin level was 10 g/dl (5.5-15). The average platelet rate was 35.5 Giga/L (27-1120). The majority of pts (120, 80%) had intermediate or high Sokal scores. The myelocytic phase was detected in 132 pts (86%), accelerated phase in 19 pts (13%), and acute transformation phase in 1 pt (1%). The indication for second-generation TKI was pts in accelerated phase in 70% of cases, failure to respond to first-generation TKI in 25% of cases, and intolerance in 5% of cases. Dasatinib was used in 75 pts (50%), nilotinib in 44 pts (30%), and dasatinib then nilotinib in 33 pts (20%). Evaluable pts (154) included 61% in MMR and 39% in failure, 25 pts died, and 25 pts were lost to follow-up. Toxicity was primarily hematological and digestive. OS was 80% at 5 years. The results obtained in our series are encouraging because second-generation TKIs as second-line therapy allowed treatment of 62% of pts who were intolerant or failing to respond to imatinib with acceptable digestive and hematological toxicity.

Low-dose dasatinib in older patients with chronic myeloid leukaemia in chronic phase (DAVLEC): a single-arm, multicentre, phase 2 trial

BCR-ABL1 tyrosine kinase inhibitors (TKIs) are commonly initiated in older patients with chronic myeloid leukaemia in the chronic phase at standard doses. However, because of their safety profile in this population, appropriate therapy has not been established. We aimed to investigate whether a lower than standard dose of dasatinib was an appropriate therapy for older patients with chronic myeloid leukaemia in the chronic phase. DAsatinib, Very Low-dose, for Elderly CML-CP patients (DAVLEC) was a multicentre, single-arm, phase 2 trial done in 25 Japanese hospitals. We enrolled patients older than 70 years with newly diagnosed chronic myeloid leukaemia in the chronic phase, ECOG performance status 0-2, and no previous treatment for CML other than hydroxyurea within 4 weeks. Second-generation TKI dasatinib was given orally at a starting dose of 20% of the standard dose (20 mg/day). If the treatment was assessed as optimal response at 3 months, 6 months, and 9 months and adverse events were grade 2 or better (according to the NCI Common Toxicity Criteria v 4.0), the same dose was continued. If response was suboptimal and adverse events were grade 2 or better, the dose was increased by 20 mg/day. Once a dose reduction had been made because of a grade 3 or worse adverse event, there were no further dose increases. Treatment was discontinued if assessed as failure (disease progression to the accelerated phase or acute phase). The primary endpoint was the achievement of major molecular response at 12 months, assessed using a per-protocol analysis. This trial is registered at with the UMIN clinical trial registry, UMIN000024548, and has completed its planned observation period. Between Nov 1, 2016, and Oct 30, 2019, 52 patients received first-line dasatinib therapy at 20 mg/day. The median age at diagnosis was 77·5 years (73·5-83·0). 35 (67%) patients were male and 17 (33%) were female. 31 (60%) of 52 patients reached major molecular response at 12 months (one-sided 95% CI 48-71), with a median follow-up of 366 days (IQR 353-372). Grade 3-4 adverse events were reported in 12 (23%) patients. Neutropenia was the most frequent grade 3-4 adverse event, occurring in three (6%) patients. No treatment-related deaths were observed. Low-dose dasatinib at 20mg/day is worthy of consideration as a starting dose for older patients with newly diagnosed chronic myeloid leukaemia in the chronic phase. However, this dose needs to be further studied in a larger cohort and with a more ethnically diverse population. Bristol-Myers Squibb.

CML-296: First-Line Treatment Outcomes of CML Patients in a Real-World Data Setting in Lebanon

Context: BCR–ABL-targeting tyrosine kinase inhibitors (TKIs) constitute the cornerstone of treatment for CML, leading to a life expectancy that is currently very close to that of age-matched individuals in the general population. Objective: To describe aspects of CML in a real-world data setting in Lebanon, including responses to first-line treatment with the first-generation TKI imatinib compared to those with the second-generation TKIs dasatinib and nilotinib. To evaluate the proportion of patients eligible for an attempt to stop TKI treatment. Design: Medical charts of patients diagnosed with CML between 2003 and 2019 were reviewed and updated in January 2020. Settings: Lebanese patients from two university medical centers in Beirut, Mount Lebanon Hospital and Hotel-Dieu de France Hospital, were included. Patients: The registry covered 70 patients, of which 54 patients were included. Inclusion criteria were patients older than 18 years, confirmed diagnosis with CML based on BCR-ABL PCR, and available follow-up data in the clinical chart for at least 2 years. Outcomes: Major and deep molecular responses were based on BCR-ABL1 levels; time of attaining these responses and duration of sustained responses were measured. The reason for switching to another TKI was noted (‘treatment failure’ or ‘intolerance’). Eligibility criteria for an attempt to stop TKI were based on the EURO-SKI trial. Modality of Treatment: Imatinib was given at a dose of 400 mg once daily, nilotinib 300 mg twice daily, and dasatinib 100 mg once daily. Results: 70% of patients were treated with imatinib and 30% with a second-generation TKI. 14% of patients discontinued their first-line treatment, mainly due to intolerance (10%) or treatment failure (5%). At 24 months, deep molecular response (MR4.0 and MR4.5) was achieved, at 15.3% and 40.3%, respectively, for imatinib, and 22% and 33.5%, respectively, for second-generation (p=1). The 5-year cumulative incidence of eligibility for TKI cessation attempt was 37%. Conclusion: We report the experience in CML from two health care institutions in Beirut, Lebanon. There was no statistically significant difference in response between the first- and second-generation TKIs. The criteria for an attempt to stop TKI therapy were met by one-third of patients.

Front-Line Treatment with Second-Generation Tyrosine Kinase Inhibitors Following By Allo-Transplantation Benefits Patients with Better Survival Inph-Positive Acute Lymphoblastic Leukemia

▪The treatment of Ph-positive acute lymphoblastic leukemia (Ph+ ALL) has entranced into tyrosine kinase inhibitors (TKIs) era. As the promising results in the treatment of chronic myeloid leukemia (CML), the second-generation TKI dasatinib has been placed as the frontline treatment of Ph+ ALL. However, who could benefit from the first line treatment of the second-generation TKIs is still unclear.Aim of this single center study is to compare the efficacy and safety of the first- and second-generation TKIs in the first-line treatment of Ph+ ALL. 77 newly diagnosed Ph+ ALL patients were enrolled and treated with TKIs combining with intensive chemotherapy, followed by allo-HSCT if donors were available. The BCR-ABL level in bone marrow was examined by RTQ-PCR and used as MRDmonitoring. 45 patients were treated with the first-generation TKI, and 32 with the second-generation TKIs. There was no significant difference in early response, including CRrate, major molecular response (MMR) and MRD negative rate between the two groups. With median follow-up of 456 (59-2327) days, a trend toward better DFS (P=0.088), but not OS (P=0.210), was seen in the patients treated with the second-generation TKIs. In subgroup analysis, both the DFS (P=0.050) and OS (P=0.048) were statistically higher in the second-generation TKIs group only if the patients received allo-HSCT.Both being treated with the second-generation TKIs and receiving allo-HSCT were multivariateanalyzedto be favorable factors for survival. There was much higher incidence of acquiring T315I mutation (4/8 vs. 1/9) after relapsed on the second-generation TKIs. In conclusion, front-line treatment of Ph+ ALL patients with the second-generation TKIs, especially dasatinib, is as effective and safe as imatinib; when allo-HSCT is incorporated as consolidation therapy following CR1, survival benefit was observed with second-generation TKIs. T315I occurred at much higher rates when patients relapsed on the second-generation TKIs and deserved further attention. DisclosuresNo relevant conflicts of interest to declare.

Dasatinib in the Management of Pediatric Patients With Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia.

Acute leukemia is the most common cancer in childhood; in particular, acute lymphoblastic leukemia (ALL) represents roughly up to 80% of all cases of acute leukemias in children. Survival of children with ALL has dramatically improved over the last few decades, and is now over 90% (versus 40% of adult patients) in developed countries, except for in infants (i.e., children < 1 year), where no significant improvement was registered. Philadelphia positive ALL (Ph+ALL) accounts for around 3% of cases of childhood ALL, its incidence increasing with patient’s age. Before the era of tyrosine-kinase inhibitors (TKIs), pediatric Ph+ALL showed a worse prognosis in comparison to other forms of ALL, and was managed with intensive chemotherapy, followed, whenever possible, by allogenic hematopoietic stem cell transplantation (HSCT) in first morphological complete remission. TKIs have revolutionized the current clinical approach, which involves combinations of imatinib plus standard chemotherapy that can abrogate the negative prognostic impact conferred by the presence of BCR/ABL1 rearrangement, resulting in the probability of event-free survival (EFS) being significantly better than that recorded in the pre-TKI era. Long-term follow-up confirms these data, questioning the role of a real advantage offered by HSCT over intensive chemotherapy plus TKI in all Ph+ALL pediatric patients. Imatinib was the first generation TKI and the prototype of targeted therapy, but over the years second- (dasatinib, nilotinib, bosutinib) and third-generation (ponatinib) TKIs showed a capacity to overcome resistance to imatinib in Ph+ hematological neoplasms. Given the effectiveness of the first-in-class TKI, imatinib, also the second-generation TKI dasatinib was incorporated in the treatment regimens of Ph+ALL. In this manuscript, we will discuss the role of this drug in pediatric Ph+ALL, analyzing the available data published to date.

Contemporary Practice Patterns of Tyrosine Kinase Inhibitor Use Among Older Patients with Chronic Myeloid Leukemia in the United States

Contemporary Practice Patterns of Tyrosine Kinase Inhibitor Use Among Older Patients with Chronic Myeloid Leukemia in the United States

Second-line Dasatinib Therapy Improved Compliance and Deep Molecular Responses in Imatinib-intolerant Chronic Myeloid Leukemia Patients.

Imatinib (IM) is the standard-of-care treatment for most chronic myeloid leukemia (CML) patients in chronic phase (CP). However, some patients suffer from low-grade side-effects that, in the long run, severely affect the quality of life and require treatment discontinuation due to toxicities. Fortunately, there are several therapeutic alternatives for these patients. Among them, the second-generation tyrosine kinase inhibitor dasatinib (DAS), used as second-line treatment, has shown to be a valid option in patients with CP-CML after intolerance to prior IM. Herein, we report on seven CP-CML patients who achieved a stable major molecular response (MMR) with IM-therapy, but were shifted to DAS treatment due to recurrent low-grade IM-intolerances (grades 1-2). All patients received conventional DAS treatment with a median daily dose of 83.3 mg. Treatment was well tolerated and side-effects were mild. In addition, after a median follow-up of 25 months (range=24-43 months) a deep molecular response (DMR) (either MR4 or MR4.5) was achieved in all patients after 24 months of treatment. This finding, although limited to a small cohort of CP-CML patients, supports the view that a therapy switch from IM to DAS induces a reduction of symptom burden, improves patient compliance and shows clinical efficacy in achieving and sustaining deep molecular responses.

Nilotinib treatment induced large granular lymphocyte expansion and maintenance of longitudinal remission in a Philadelphia chromosome-positive acute lymphoblastic leukemia

It is well known that the second-generation tyrosine kinase inhibitor dasatinib evokes an immunological reaction as an off-target effect and induces large granular lymphocytes (LGLs) expansion in 30% of patients. However, LGLs expansion in nilotinib-treated patients is rare. We report the case of a 65-year-old patient with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) who showed LGLs expansion during nilotinib treatment. The patient achieved complete remission (CR) after multi-agent chemotherapy combined with dasatinib treatment. However, ALL relapsed in the central nervous system and bone marrow when treatment was interrupted due to interstitial pneumonia. Nilotinib treatment was subsequently started and the patient achieved second CR. Marked peripheral blood lymphocytosis emerged after the start of nilotinib treatment. CD8 + CD57 + cytotoxic T cells were predominantly expanded and showed strong cytocidal activity against K562 Ph-positive leukemia cells. These results suggest that similar to dasatinib, nilotinib can induce LGLs expansion, possibly contributing to long-term remission in patients with Ph-ALL.

Dasatinib-Blinatumomab Combination for the Front-Line Treatment of Adult Ph+ ALL Patients. Updated Results of the Gimema LAL2116 D-Alba Trial

Dasatinib-Blinatumomab Combination for the Front-Line Treatment of Adult Ph+ ALL Patients. Updated Results of the Gimema LAL2116 D-Alba Trial

Treatment Effects of the Second-Generation Tyrosine Kinase Inhibitor Dasatinib on Autoimmune Arthritis.

Rheumatoid arthritis (RA) is a multifactorial autoimmune disease that primarily manifests as persistent synovitis and progressive joint destruction. Imatinib exhibited a therapeutic effect in murine collagen-induced arthritis (CIA) via selective inhibition tyrosine kinases. The second-generation tyrosine kinase inhibitor dasatinib exhibits more durable hematological and cytogenetic effects and more potency compared to imatinib. However, the effect of dasatinib on CIA is poorly understood. The present study investigated the treatment effect of dasatinib on autoimmune arthritis. We demonstrated that dasatinib alleviated arthritis symptoms and histopathological destruction in CIA mice. Dasatinib treatment inhibited the production of proinflammatory cytokines including IL-1β, TNF-α, and IL-6, and promoted the production of the anti-inflammatory cytokine IL-10. Dasatinib treatment also suppressed the expression of anti-mouse CII antibodies including total IgG, IgG1, IgG2, and IgG2b, in CIA mice. We further demonstrated that dasatinib inhibited the migration and proliferation of fibroblast-like synoviocytes (FLS) from RA patients and promoted FLS apoptosis. The mRNA expression of MMP13, VEGF, FGF, and DKK1 was down-regulated in FLS treated with dasatinib. Our findings suggest that dasatinib exhibited treatment effects on CIA mice and that FLS are an important target cell of dasatinib treatment in autoimmune arthritis.

Cardiovascular Hospitalization in Patients Treated with Dasatinib or Nilotinib in Simplicity, an Observational Study of Chronic-Phase Chronic Myeloid Leukemia (CP-CML) Patients in Routine Clinical Practice

Introduction: The combined effect of cardiovascular (CV) risk and tyrosine kinase inhibitor (TKI) therapy may contribute to the incidence of CV events in patients (pts) with chronic phase chronic myeloid leukemia (CP-CML). CV events can affect the overall clinical outcomes and survival of CML patients, and hospitalization due to CV events is costly; analyzing the rates and risks of CV hospitalization in pts with CML receiving TKI therapy may help to inform treatment decisions and risk mitigation strategies and to minimize costs. SIMPLICITY (NCT01244750) is an ongoing observational study of CP-CML pts in routine clinical practice receiving first-line (1L) TKIs since 2010 in the US and Europe, exploring TKI use and management patterns in clinical practice. This analysis aims to evaluate rates of CV-related hospitalization and estimate related costs in pts treated with the second-generation TKIs dasatinib (DAS) and nilotinib (NIL).Methods: CV hospitalizations were identified retrospectively from events reported by SIMPLICITY investigators over the course of treatment with DAS or NIL, from the start of treatment (any line of therapy) to 30 days after the end of that line of therapy, or prior to the start of a subsequent line of TKI therapy, whichever was sooner. Pts were followed for a maximum of five years. Owing to the observational nature of SIMPLICITY, patients were not matched between cohorts and adjustments for covariates were not made. Kaplan-Meier methods with the log-rank test were used to estimate time to first CV hospitalization. Statistical comparisons were made using t-tests and the Mann-Whitney U test for continuous variables and chi square for categorical variables.Results: Overall, 825 pts received DAS (n=417) or NIL (n=408) as 1L therapy; 376 pts received DAS (n=214) or NIL (n=162) as second-line (2L) therapy; and 124 pts received DAS (n=63) or NIL (n=61) as third-line (3L) therapy. See table for patient baseline demographics and comorbidities. No significant differences were noted between the DAS and NIL cohorts. Median age was similar between the DAS and NIL groups at 56.2 and 54.1 years. At baseline, both groups had similar CV comorbidities. A significantly greater number of pts were treated in the US vs Europe (p=0.017).Investigators reported that, during 1L DAS and NIL therapy, 43% (n=357) of pts experienced a CV disorder: 45.3% (n=189) of DAS pts and 41.2% (n=168) of NIL pts (DAS vs NIL, p=0.28). Numbers of CV-related hospitalizations occurring during DAS and NIL therapy were 16 and 36, respectively, translating to 12.6 and 27.4 CV-related hospitalizations per 1000 pt years. Across 1L, 2L, and 3L (referred to here as ‘all lines‘) of DAS and NIL therapy, 31 and 51 CV-related hospitalizations occurred, translating to 16.7 and 28.8 CV-related hospitalizations per 1000 pt years, respectively. The three most common CV-related reasons for hospitalization were congestive cardiac failure, atrial fibrillation and myocardial infarction. The figure shows Kaplan-Meier curves of time to first CV-related hospitalization for 1L therapy, for five years of follow-up. CV-related hospitalization at 5 years of follow-up was 5% for pts on 1L DAS, 7.5% for pts on 1L NIL, 5.7% for all lines of DAS and 8.5% for all lines of NIL. Durations of hospital stay related to CV disorders for pts on 1L DAS and 1L NIL were 68 days and 263 days, translating to 53.3 and 199.8 days in hospital per 1000 pt years. Durations of hospital stay related to CV disorders for pts on all lines of DAS and NIL were 107.4 days and 226.1 days, translating to 53.3 and 199.8 days in hospital per 1000 pt years. Incremental cost differences based on mean estimates will be presented.Conclusions: CV disorders and related hospitalizations were frequently seen in patients with CP-CML in SIMPLICITY. In these patients, NIL was associated with a rate of CV hospitalization up to double that associated with DAS and lengthier hospital stay. Owing to the survival benefits conferred by TKIs, it is critical to minimize and manage complications that may arise in treated pts; potential for greater morbidity and healthcare cost should be considered when making decisions about TKIs to use in individual pts, particularly those with preexisting CV comorbidities. [Display omitted] DisclosuresMauro:Pfizer: Consultancy; Bristol-Myers Squibb: Consultancy; Takeda: Consultancy; Novartis: Consultancy, Research Funding. Chen:Bristol-Myers Squibb: Employment. Cortes:Novartis: Consultancy, Research Funding; Arog: Research Funding; Astellas Pharma: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding. Gambacorti-Passerini:Pfizer: Consultancy, Honoraria, Research Funding; BMS: Consultancy. Sen:ICON PLC: Employment. Gajavelli:Bristol-Myers Squibb: Employment. Davis:Bristol-Myers Squibb: Employment. Michallet:Octapharma: Membership on an entity's Board of Directors or advisory committees; Chugai: Consultancy; Novartis: Research Funding.

Pattern of Use and Long-Term Safety of Tyrosine Kinase Inhibitors: A Decade of Real-World Management of Chronic Myeloid Leukemia.

First-line treatment of chronic phase (CP) chronic myeloid leukemia (CML) is based on the first-generation tyrosine kinase inhibitor (TKI) imatinib or the second-generation TKIs dasatinib or nilotinib. Thanks to the efficacy of TKIs, CML has switched from a fatal to a 'chronic' pathology, and data from clinical trials have become insufficient to drive physicians' prescription choices and address long-term treatment outcomes. On the brink of commercialization of generic imatinib, this study aims to evaluate the therapeutic pattern of CP-CML and the occurrence of adverse events (AEs) over a decade of local real clinical practice. A retrospective cohort study was performed on CP-CML patients followed up in the Local Health Unit of Treviso (Veneto Region, Italy) during the period 2005-2015. Data were captured from both administrative databases and physicians' patient diaries. Of 81 CP-CML patients, 73 were treated with first-line imatinib; among the second-generation TKIs, only nilotinib was used (n=8). Overall, 38% of imatinib-treated subjects needed to switch, mainly due to intolerance, whereas no switches occurred in the nilotinib cohort. Osteoarticular pain was the most common AE and was significantly more frequent in the imatinib cohort (68.49 vs. 25.00%, p=0.022). Other common AEs were dermatologic manifestations, asthenia, and diarrhea. Although based on a small population, this study represents an unbiased reference on the long-term management of CML in an Italian clinical setting. Our results indicate a better profile of first-line nilotinib, both in terms of persistency and tolerability. AEs remain a major concern, highlighting the importance of close monitoring.

Glucosylated nanomicelles target glucose-avid pediatric patient-derived sarcomas

We report for the first time on a nano-drug delivery system based on glucosylated polymeric nanomicelles to actively target the second-generation tyrosine kinase inhibitor dasatinib to glucose-avid pediatric sarcomas by the intravenous route. After a comprehensive physicochemical characterization that confirmed the substantially lower critical micellar concentration and the higher encapsulation capacity of the glucosylated amphiphilic nanocarrier with respect to the pristine counterpart, we showed a 9-fold decrease of the half maximal inhibitory concentration of dasatinib in a rhabdomyosarcoma cell line, Rh30, in vitro. In immunodeficient mice bearing the glucose-avid Rh30 xenograft, we revealed that the glucosylated polymeric nanomicelles increased the delivery of dasatinib in the tumor parenchyma. Conversely, the exposure of off-target tissues and organs to the drug was substantially reduced. Upon experimental confirmation that most patient-derived xenograft (PDX) models of pediatric sarcomas overexpress glucose transporter 1 (GLUT-1), we demonstrated the selective accumulation of dasatinib in a patient-derived rhabdomyosarcoma model in vivo. Conversely, the reference dose administered by the oral route was not tumor-selective. Finally, the improved nanocarrier pharmacokinetics led to prolonged median survival of mice bearing a clinically relevant PDX model of alveolar rhabdomyosarcoma from 19 days for the untreated controls to 27 days for the targeted therapy.

Dasatinib dose management for the treatment of chronic myeloid leukemia.

Chronic myeloid leukemia (CML) has evolved into a chronic disease that is managed with tyrosine kinase inhibitor therapy. Now that long‐term survival has been achieved in patients with CML, the focus of treatment has shifted to dose optimization, with the goal of maintaining response while improving quality of life. In this review, the authors discuss optimizing the dose of the second‐generation tyrosine kinase inhibitor dasatinib. Once‐daily dosing regimens for dasatinib in the first and later lines of treatment were established through long‐term (5‐year and 7‐year) trials. Recently published data have indicated that further dose optimization may maintain efficacy while minimizing adverse events. Results obtained from dose optimization and discontinuation trials currently in progress will help practitioners determine the best dose and duration of dasatinib for patients with CML, because treatment decisions will be made through continued discussions between physicians and patients. Cancer 2018;124:1660‐72. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Towards Comprehension of the ABCB1/P-Glycoprotein Role in Chronic Myeloid Leukemia.

The introduction of imatinib (IM), a BCR-ABL1 tyrosine kinase inhibitor (TKI), has represented a significant advance in the first-line treatment of chronic myeloid leukemia (CML). However, approximately 30% of patients need to discontinue IM due to resistance or intolerance to this drug. Both resistance and intolerance have also been observed in treatment with the second-generation TKIs—dasatinib, nilotinib, and bosutinib—and the third-generation TKI—ponatinib. The mechanisms of resistance to TKIs may be BCR-ABL1-dependent and/or BCR-ABL1-independent. Although the role of efflux pump P-glycoprotein (Pgp), codified by the ABCB1 gene, is unquestionable in drug resistance of many neoplasms, a longstanding question exists about whether Pgp has a firm implication in TKI resistance in the clinical scenario. The goal of this review is to offer an overview of ABCB1/Pgp expression/activity/polymorphisms in CML. Understanding how interactions, associations, or cooperation between Pgp and other molecules—such as inhibitor apoptosis proteins, microRNAs, or microvesicles—impact IM resistance risk may be critical in evaluating the response to TKIs in CML patients. In addition, new non-TKI compounds may be necessary in order to overcome the resistance mediated by Pgp in CML.

Dasatinib for the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia：report of ten cases and review of literature

Objective To observe the clinical response and safety of second-generation tyrosine kinase inhibitor dasatinib in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia(Ph + ALL). Methods The clinical data of 10 adult Ph + ALL patients treated with dasatinib were analyzed with review of literatures. Results All the 10 Ph + ALL patients treated with dasatinib achieved remission in 7 weeks, including 9 cases of complete remission[7 cases achieved complete molecular remission(CRm)in 13 weeks]. The median overall survival time(OS)was 13.8 months(5-33), and the median disease-free survival(DFS)time was 10.8 months(4-25). There were 3 cases of pleural effusion, 4 cases of Ⅳ degree of bone marrow suppression and 6 cases of extremely low blood platelet, which could be that was improved via by symptomatic treatment and, with no case of the death occurred during the treatment of dasatinib, the safety was high. Conclusion Dasatinib can deepen molecular biological reaction and prolonged the survival time of patients in the treatment of adult Ph+ ALL, with high remission rate and safety, and which can be considered as first-line treatment. Key words: Dasatinib; Philadelphia chromosome; Leukemia, lymphoblastic, acute